Surgical shaft assemblies with slip ring assemblies forming capacitive channels

ABSTRACT

A surgical shaft assembly includes a slip ring assembly. The slip ring assembly has a first connector, a first conductor mounted on the first connector, and a first water-proof insulative layer on the first conductor. The slip ring assembly has a second connector rotatable relative to the first connector, a second conductor mounted on the second connector, and a second water-proof insulative layer on the second conductor. The slip ring assembly also has a dielectric layer located between the first water-proof insulative layer and the second water-proof insulative layer. The first conductor and the second conductor are configured to form a capacitive channel therebetween.

TECHNICAL FIELD

The present disclosure relates to surgical instruments and, in various circumstances, to surgical stapling and cutting instruments and staple cartridges therefor that are designed to staple and cut tissue.

BACKGROUND

In a motorized surgical stapling and cutting instrument it may be useful to measure the position and velocity of a cutting member in an initial predetermined time or displacement to control speed. Measurement of position or velocity over an initial predetermined time or displacement may be useful to evaluate tissue thickness and to adjust the speed of the remaining stroke based on this comparison against a threshold.

While several devices have been made and used, it is believed that no one prior to the inventors has made or used the device described in the appended claims.

SUMMARY

A shaft assembly is usable with a surgical instrument. The shaft assembly defines a longitudinal axis extending longitudinally through the shaft assembly. The shaft assembly includes a proximal shaft portion including a first sensor and a second sensor. The shaft assembly also includes a distal shaft portion rotatable about the longitudinal axis and relative to the proximal shaft portion. The distal shaft portion includes housing, a first magnet rotatable with the housing, a clutch assembly rotatable relative to the housing to transition the shaft assembly between an articulation engaged state and an articulation disengaged state, and a second magnet rotatable with the clutch assembly. The shaft assembly further includes a control circuit configured to detect a transition from the articulation engaged state to the articulation disengaged state based on output signals from the first sensor and the second sensor.

A shaft assembly is usable with a surgical instrument. The shaft assembly defines a longitudinal axis extending longitudinally through the shaft assembly. The shaft assembly includes a proximal shaft portion including a first sensor and a second sensor. The shaft assembly also includes a distal shaft portion rotatable about the longitudinal axis and relative to the proximal shaft portion. The distal shaft portion includes a housing, a first magnet rotatable with the housing, a clutch assembly rotatable relative to the housing to transition the shaft assembly between an articulation engaged state and an articulation disengaged state, and a second magnet rotatable with the clutch assembly. The shaft assembly further includes a control circuit configured to detect a transition from the articulation engaged state to the articulation disengaged state based on relative rotational positions of the distal shaft portion of the shaft assembly and the clutch assembly.

A shaft assembly is usable with a surgical instrument. The shaft assembly defines a longitudinal axis extending longitudinally through the shaft assembly. The shaft assembly includes a proximal shaft portion including a first sensor configured to generate a first output signal and a second sensor configured to generate a second output signal. The shaft assembly also includes a distal shaft portion. The distal shaft portion includes a clutch assembly rotatable with the distal shaft portion about the longitudinal axis and relative to the proximal shaft portion. The clutch assembly is further rotatable relative to the distal shaft portion to transition the shaft assembly between an articulation engaged state and an articulation disengaged state. The rotation of clutch assembly with the distal shaft portion changes the first output signal. The rotation of the clutch assembly relative to the distal shaft portion changes the second output signal. The shaft assembly also includes a control circuit in electrical communication with the first sensor and the second sensor, wherein the control circuit is configured to detect a change in the second output signal occurring without a corresponding change in the first output signal, and wherein the detected change indicates a transition between the articulation engaged state and the articulation disengaged state.

A surgical instrument includes a surgical end effector, a control circuit, and a connector assembly. The connector assembly includes a first connector comprising a first conductor electrically coupled to the surgical end effector, and a second connector comprising a second conductor spaced apart from the first conductor, wherein the second conductor is electrically coupled to the control circuit, wherein the first connector is rotatable relative to the second connector, wherein the first conductor is capacitively coupled to the second conductor defining a capacitive channel therebetween for transmitting an electrical signal between the end effector and the control circuit.

A surgical instrument includes a surgical end effector, an energy source, and a connector assembly. The connector assembly includes a first connector comprising a first conductor electrically coupled to the surgical end effector, and a second connector comprising a second conductor spaced apart from the first conductor, wherein the second conductor is electrically coupled to the energy source, wherein the first connector is rotatable relative to the second connector, wherein the first conductor is capacitively coupled to the second conductor defining a capacitive channel therebetween for transmitting energy from the energy source to the end effector.

FIGURES

The novel features of the various aspects described herein are set forth with particularity in the appended claims. The various aspects, however, both as to organization and methods of operation may be better understood by reference to the following description, taken in conjunction with the accompanying drawings as follows:

FIG. 1 is a perspective view of a surgical instrument that has a shaft assembly and an end effector in accordance with one or more aspects of the present disclosure.

FIG. 2 is an exploded assembly view of a portion of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

FIG. 3 is an exploded view of an end effector of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

FIG. 4 is perspective view of an RF cartridge and an elongate channel adapted for use with the RF cartridge according to one aspect of the present disclosure.

FIG. 5 is an exploded assembly view of portions of the interchangeable shaft assembly of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

FIG. 6 is another exploded assembly view of portions of the interchangeable shaft assembly of FIG. 1 according to one aspect of this disclosure.

FIG. 7 is a cross-sectional view of a portion of the interchangeable shaft assembly of FIG. 1 according to one aspect of this disclosure.

FIG. 8 is a perspective view of a portion of the shaft assembly of FIG. 1 with the switch drum omitted for clarity.

FIG. 9 is another perspective view of the portion of the interchangeable shaft assembly of FIG. 1 with the switch drum mounted thereon.

FIG. 10 is a perspective partial cut-away view of a slip ring assembly according to one aspect of this disclosure.

FIG. 11 is a cross-sectional view of a portion of the slip ring assembly of FIG. 10 according to one aspect of this disclosure.

FIG. 12 is a cross-sectional view of a portion of a slip ring assembly according to one aspect of this disclosure.

FIG. 13 is a block diagram of a circuit of a surgical instrument, illustrating interfaces between a control circuit, a power source, a slip ring assembly, and an end effector according to one aspect of this disclosure.

DESCRIPTION

Applicant of the present application owns the following U.S. Patent Applications that were filed on even date herewith and which are each herein incorporated by reference in their respective entireties:

U.S. patent application Ser. No. ______, entitled ARTICULATION STATE DETECTION MECHANISMS; Attorney Docket No. END8176USNP/170049; U.S. patent application Ser. No. ______, entitled SURGICAL SHAFT ASSEMBLIES WITH INCREASED CONTACT PRESSURE; Attorney Docket No. END8177USNP/170050; U.S. patent application Ser. No. ______, entitled METHOD OF COATING SLIP RINGS; Attorney Docket No. END8179USNP/170052; U.S. patent application Ser. No. ______, entitled SURGICAL SHAFT ASSEMBLIES WITH WATERTIGHT HOUSINGS; Attorney Docket No. END8180USNP/170053; and U.S. patent application Ser. No. ______, entitled SURGICAL SHAFT ASSEMBLIES WITH FLEXIBLE INTERFACES; Attorney Docket No. END8223USNP/170126.

Certain aspects are shown and described to provide an understanding of the structure, function, manufacture, and use of the disclosed devices and methods. Features shown or described in one example may be combined with features of other examples and modifications and variations are within the scope of this disclosure.

The terms “proximal” and “distal” are relative to a clinician manipulating the handle of the surgical instrument where “proximal” refers to the portion closer to the clinician and “distal” refers to the portion located further from the clinician. For expediency, spatial terms “vertical,” “horizontal,” “up,” and “down” used with respect to the drawings are not intended to be limiting and/or absolute, because surgical instruments can used in many orientations and positions.

The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a surgical system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, an element of a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features.

Example devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. Such devices and methods, however, can be used in other surgical procedures and applications including open surgical procedures, for example. The surgical instruments can be inserted into a through a natural orifice or through an incision or puncture hole formed in tissue. The working portions or end effector portions of the instruments can be inserted directly into the body or through an access device that has a working channel through which the end effector and elongated shaft of the surgical instrument can be advanced.

FIGS. 1-9 depict a motor-driven surgical instrument 10 for cutting and fastening that may or may not be reused. In the illustrated examples, the surgical instrument 10 includes a housing 12 that comprises a handle assembly 14 that is configured to be grasped, manipulated, and actuated by the clinician. The housing 12 is configured for operable attachment to an interchangeable shaft assembly 200 that has an end effector 300 operably coupled thereto that is configured to perform one or more surgical tasks or procedures. In accordance with the present disclosure, various forms of interchangeable shaft assemblies may be effectively employed in connection with robotically controlled surgical systems. The term “housing” may encompass a housing or similar portion of a robotic system that houses or otherwise operably supports at least one drive system configured to generate and apply at least one control motion that could be used to actuate interchangeable shaft assemblies. The term “frame” may refer to a portion of a handheld surgical instrument. The term “frame” also may represent a portion of a robotically controlled surgical instrument and/or a portion of the robotic system that may be used to operably control a surgical instrument. Interchangeable shaft assemblies may be employed with various robotic systems, instruments, components, and methods disclosed in U.S. Pat. No. 9,072,535, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, which is herein incorporated by reference in its entirety.

FIG. 1 is a perspective view of a surgical instrument 10 that has an interchangeable shaft assembly 200 operably coupled thereto according to one aspect of this disclosure. The housing 12 includes an end effector 300 that comprises a surgical cutting and fastening device configured to operably support a surgical staple cartridge 304 therein. The housing 12 may be configured for use in connection with interchangeable shaft assemblies that include end effectors that are adapted to support different sizes and types of staple cartridges, have different shaft lengths, sizes, and types. The housing 12 may be employed with a variety of interchangeable shaft assemblies, including assemblies configured to apply other motions and forms of energy such as, radio frequency (RF) energy, ultrasonic energy, and/or motion to end effector arrangements adapted for use in connection with various surgical applications and procedures. The end effectors, shaft assemblies, handles, surgical instruments, and/or surgical instrument systems can utilize any suitable fastener, or fasteners, to fasten tissue. For instance, a fastener cartridge comprising a plurality of fasteners removably stored therein can be removably inserted into and/or attached to the end effector of a shaft assembly.

The handle assembly 14 may comprise a pair of interconnectable handle housing segments 16, 18 interconnected by screws, snap features, adhesive, etc. The handle housing segments 16, 18 cooperate to form a pistol grip portion 19 that can be gripped and manipulated by the clinician. The handle assembly 14 operably supports a plurality of drive systems configured to generate and apply control motions to corresponding portions of the interchangeable shaft assembly that is operably attached thereto.

FIG. 2 is an exploded assembly view of a portion of the surgical instrument 10 of FIG. 1 according to one aspect of this disclosure. The handle assembly 14 may include a frame 20 that operably supports a plurality of drive systems. The frame 20 can operably support a “first” or closure drive system 30, which can apply closing and opening motions to the interchangeable shaft assembly 200. The closure drive system 30 may include an actuator such as a closure trigger 32 pivotally supported by the frame 20. The closure trigger 32 is pivotally coupled to the handle assembly 14 by a pivot pin 33 to enable the closure trigger 32 to be manipulated by a clinician. When the clinician grips the pistol grip portion 19 of the handle assembly 14, the closure trigger 32 can pivot from a starting or “unactuated” position to an “actuated” position and more particularly to a fully compressed or fully actuated position.

The handle assembly 14 and the frame 20 may operably support a firing drive system 80 configured to apply firing motions to corresponding portions of the interchangeable shaft assembly attached thereto. The firing drive system 80 may employ an electric motor 82 located in the pistol grip portion 19 of the handle assembly 14. The electric motor 82 may be a DC brushed motor having a maximum rotational speed of approximately 25,000 RPM, for example. In other arrangements, the motor may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The electric motor 82 may be powered by a power source 90 that may comprise a removable power pack 92. The removable power pack 92 may comprise a proximal housing portion 94 configured to attach to a distal housing portion 96. The proximal housing portion 94 and the distal housing portion 96 are configured to operably support a plurality of batteries 98 therein. Batteries 98 may each comprise, for example, a Lithium Ion (LI) or other suitable battery. The distal housing portion 96 is configured for removable operable attachment to a control circuit board 100, which is operably coupled to the electric motor 82. Several batteries 98 connected in series may power the surgical instrument 10. The power source 90 may be replaceable and/or rechargeable.

The electric motor 82 can include a rotatable shaft (not shown) that operably interfaces with a gear reducer assembly 84 mounted in meshing engagement with a with a set, or rack, of drive teeth 122 on a longitudinally movable drive member 120. The longitudinally movable drive member 120 has a rack of drive teeth 122 formed thereon for meshing engagement with a corresponding drive gear 86 of the gear reducer assembly 84.

In use, a voltage polarity provided by the power source 90 can operate the electric motor 82 in a clockwise direction wherein the voltage polarity applied to the electric motor by the battery can be reversed in order to operate the electric motor 82 in a counter-clockwise direction. When the electric motor 82 is rotated in one direction, the longitudinally movable drive member 120 will be axially driven in the distal direction “DD.” When the electric motor 82 is driven in the opposite rotary direction, the longitudinally movable drive member 120 will be axially driven in a proximal direction “PD.” The handle assembly 14 can include a switch that can be configured to reverse the polarity applied to the electric motor 82 by the power source 90. The handle assembly 14 may include a sensor configured to detect the position of the longitudinally movable drive member 120 and/or the direction in which the longitudinally movable drive member 120 is being moved.

Actuation of the electric motor 82 can be controlled by a firing trigger 130 that is pivotally supported on the handle assembly 14. The firing trigger 130 may be pivoted between an unactuated position and an actuated position.

Turning back to FIG. 1, the interchangeable shaft assembly 200 includes an end effector 300 comprising an elongated channel 302 configured to operably support a surgical staple cartridge 304 therein. The end effector 300 may include an anvil 306 that is pivotally supported relative to the elongated channel 302. The interchangeable shaft assembly 200 may include an articulation joint 270. Construction and operation of the end effector 300 and the articulation joint 270 are set forth in U.S. Patent Application Publication No. 2014/0263541, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, which is herein incorporated by reference in its entirety. The interchangeable shaft assembly 200 may include a proximal housing or nozzle 201 comprised of nozzle portions 202, 203. The interchangeable shaft assembly 200 may include a closure tube 260 extending along a shaft axis SA that can be utilized to close and/or open the anvil 306 of the end effector 300.

Turning back to FIG. 1, the closure tube 260 is translated distally (direction “DD”) to close the anvil 306, for example, in response to the actuation of the closure trigger 32 in the manner described in the aforementioned reference U.S. Patent Application Publication No. 2014/0263541. The anvil 306 is opened by proximally translating the closure tube 260. In the anvil-open position, the closure tube 260 is moved to its proximal position.

FIG. 3 is an exploded view of one aspect of an end effector 300 of the surgical instrument 10 of FIG. 1 in accordance with one or more aspects of the present disclosure. The end effector 300 may include the anvil 306 and the surgical staple cartridge 304. In this non-limiting example, the anvil 306 is coupled to an elongated channel 302. For example, apertures 199 can be defined in the elongated channel 302 which can receive pins 152 extending from the anvil 306 and allow the anvil 306 to pivot from an open position to a closed position relative to the elongated channel 302 and surgical staple cartridge 304. A firing bar 172 is configured to longitudinally translate into the end effector 300. The firing bar 172 may be constructed from one solid section, or in various examples, may include a laminate material comprising, for example, a stack of steel plates. The firing bar 172 comprises an E-beam 178 and a cutting edge 182 at a distal end thereof. In various aspects, the E-beam may be referred to as an I-beam. A distally projecting end of the firing bar 172 can be attached to the E-beam 178 element in any suitable manner and can, among other things, assist in spacing the anvil 306 from a surgical staple cartridge 304 positioned in the elongated channel 302 when the anvil 306 is in a closed position. The E-beam 178 also can include a sharpened cutting edge 182 that can be used to sever tissue as the E-beam 178 is advanced distally by the firing bar 172. In operation, the E-beam 178 also can actuate, or fire, the surgical staple cartridge 304. The surgical staple cartridge 304 can include a molded cartridge body 194 that holds a plurality of staples 191 resting upon staple drivers 192 within respective upwardly open staple cavities 195. A wedge sled 190 is driven distally by the E-beam 178, sliding upon a cartridge tray 196 that holds together the various components of the surgical staple cartridge 304. The wedge sled 190 upwardly cams the staple drivers 192 to force out the staples 191 into deforming contact with the anvil 306 while the cutting edge 182 of the E-beam 178 severs clamped tissue.

The E-beam 178 can include upper pins 180 that engage the anvil 306 during firing. The E-beam 178 can further include middle pins 184 and a bottom foot 186 that can engage various portions of the cartridge body 194, cartridge tray 196, and elongated channel 302. When a surgical staple cartridge 304 is positioned within the elongated channel 302, a slot 193 defined in the cartridge body 194 can be aligned with a longitudinal slot 197 defined in the cartridge tray 196 and a slot 189 defined in the elongated channel 302. In use, the E-beam 178 can slide through the aligned longitudinal slots 193, 197, and 189 wherein, as indicated in FIG. 3, the bottom foot 186 of the E-beam 178 can engage a groove running along the bottom surface of elongated channel 302 along the length of slot 189, the middle pins 184 can engage the top surfaces of cartridge tray 196 along the length of longitudinal slot 197, and the upper pins 180 can engage the anvil 306. In such circumstances, the E-beam 178 can space, or limit the relative movement between, the anvil 306 and the surgical staple cartridge 304 as the firing bar 172 is moved distally to fire the staples from the surgical staple cartridge 304 and/or incise the tissue captured between the anvil 306 and the surgical staple cartridge 304. Thereafter, the firing bar 172 and the E-beam 178 can be retracted proximally allowing the anvil 306 to be opened to release the two stapled and severed tissue portions.

Referring to FIG. 4, in at least one arrangement, an interchangeable shaft assembly can be used in connection with an RF cartridge 1700 as well as a surgical staple/fastener cartridge.

The RF surgical cartridge 1700 includes a cartridge body 1710 that is sized and shaped to be removably received and supported in the elongate channel 1602. For example, the cartridge body 1710 may be configured to be removable retained in snap engagement with the elongate channel 1602. In at least one aspect, the cartridge body 1710 includes a centrally disposed elongate slot 1712 that extends longitudinally through the cartridge body to accommodate longitudinal travel of a knife therethrough.

The cartridge body 1710 is formed with a centrally disposed raised electrode pad 1720. The elongate slot 1712 extends through the center of the electrode pad 1720 and serves to divide the pad 1720 into a left pad segment 1720L and a right pad segment 1720R. A right flexible circuit assembly 1730R is attached to the right pad segment 1720R and a left flexible circuit assembly 1730L is attached to the left pad segment 1720L. In at least one arrangement for example, the right flexible circuit 1730R comprises a plurality of wires 1732R that may include, for example, wider wires/conductors for RF purposes and thinner wires for conventional stapling purposes that are supported or attached or embedded into a right insulator sheath/member 1734R that is attached to the right pad 1720R. In addition, the right flexible circuit assembly 1730R includes a “phase one”, proximal right electrode 1736R and a “phase two” distal right electrode 1738R. Likewise, the left flexible circuit assembly 1730L comprises a plurality of wires 1732L that may include, for example, wider wires/conductors for RF purposes and thinner wires for conventional stapling purposes that are supported or attached or embedded into a left insulator sheath/member 1734L that is attached to the left pad 1720L. In addition, the left flexible circuit assembly 1730L includes a “phase one”, proximal left electrode 1736L and a “phase two” distal left electrode 1738L. The left and right wires 1732L, 1732R are attached to a distal micro-chip 1740 mounted to the distal end portion of the cartridge body 1710.

The elongate channel 1602 includes a channel circuit 1670 that is supported in a recess 1621 that extends from the proximal end of the elongate channel 1602 to a distal location 1623 in the elongate channel bottom portion 1620. The channel circuit 1670 includes a proximal contact portion 1672 that contacts a distal contact portion 1169 of a flexible shaft circuit strip for electrical contact therewith. A distal end 1674 of the channel circuit 1670 is received within a corresponding wall recess 1625 formed in one of the channel walls 1622 and is folded over and attached to an upper edge 1627 of the channel wall 1622. A serial of corresponding exposed contacts 1676 are provided in the distal end 1674 of the channel circuit 1670. An end of a flexible cartridge circuit 1750 is attached to the distal micro-chip 1740 and is affixed to the distal end portion of the cartridge body 1710. Another end is folded over the edge of the cartridge deck surface 1711 and includes exposed contacts configured to make electrical contact with the exposed contacts 1676 of the channel circuit 1670. Thus, when the RF cartridge 1700 is installed in the elongate channel 1602, the electrodes as well as the distal micro-chip 1740 are powered and communicate with an onboard circuit board through contact between the flexible cartridge circuit 1750, the flexible channel circuit 1670, a flexible shaft circuit and slip ring assembly.

FIG. 5 is another exploded assembly view of portions of the interchangeable shaft assembly 200 according to one aspect of this disclosure. The interchangeable shaft assembly 200 includes a firing member 220 that is supported for axial travel within a shaft spine 210. The firing member 220 includes an intermediate firing shaft portion 222 that is configured for attachment to a distal portion or bar 280. The intermediate firing shaft portion 222 may include a longitudinal slot 223 in the distal end thereof which can be configured to receive a tab 284 on the proximal end 282 of the distal bar 280. The longitudinal slot 223 and the proximal end 282 can be sized and configured to permit relative movement therebetween and can comprise a slip joint 286. The slip joint 286 can permit the intermediate firing shaft portion 222 of the firing member 220 to be moved to articulate the end effector 300 without moving, or at least substantially moving, the bar 280. Once the end effector 300 has been suitably oriented, the intermediate firing shaft portion 222 can be advanced distally until a proximal sidewall of the longitudinal slot 223 comes into contact with the tab 284 in order to advance the distal bar 280. Advancement of the distal bar 280 causes the E-beam 178 to be advanced distally to fire the staple cartridge positioned within the channel 302.

Further to the above, the shaft assembly 200 includes a clutch assembly 400 which can be configured to selectively and releasably couple the articulation driver 230 to the firing member 220. In one form, the clutch assembly 400 includes a lock collar, or sleeve 402, positioned around the firing member 220 wherein the lock sleeve 402 can be rotated between an engaged position in which the lock sleeve 402 couples the articulation drive 230 to the firing member 220 and a disengaged position in which the articulation drive 230 is not operably coupled to the firing member 220. When lock sleeve 402 is in its engaged position, distal movement of the firing member 220 can move the articulation drive 230 distally and, correspondingly, proximal movement of the firing member 220 can move the articulation drive 230 proximally. When lock sleeve 402 is in its disengaged position, movement of the firing member 220 is not transmitted to the articulation drive 230 and, as a result, the firing member 220 can move independently of the articulation drive 230.

The lock sleeve 402 can comprise a cylindrical, or an at least substantially cylindrical, body including a longitudinal aperture 403 defined therein configured to receive the firing member 220. The lock sleeve 402 can comprise diametrically-opposed, inwardly-facing lock protrusions 404 and an outwardly-facing lock member 406. The lock protrusions 404 can be configured to be selectively engaged with the firing member 220. More particularly, when the lock sleeve 402 is in its engaged position, the lock protrusions 404 are positioned within a drive notch 224 defined in the firing member 220 such that a distal pushing force and/or a proximal pulling force can be transmitted from the firing member 220 to the lock sleeve 402. When the lock sleeve 402 is in its engaged position, the second lock member 406 is received within a drive notch 232 defined in the articulation driver 230 such that the distal pushing force and/or the proximal pulling force applied to the lock sleeve 402 can be transmitted to the articulation driver 230. In effect, the firing member 220, the lock sleeve 402, and the articulation driver 230 will move together when the lock sleeve 402 is in its engaged position. On the other hand, when the lock sleeve 402 is in its disengaged position, the lock protrusions 404 may not be positioned within the drive notch 224 of the firing member 220 and, as a result, a distal pushing force and/or a proximal pulling force may not be transmitted from the firing member 220 to the lock sleeve 402. Correspondingly, the distal pushing force and/or the proximal pulling force may not be transmitted to the articulation driver 230. In such circumstances, the firing member 220 can be slid proximally and/or distally relative to the lock sleeve 402 and the proximal articulation driver 230.

The shaft assembly 200 further includes a switch drum 500 that is rotatably received on the closure tube 260. The switch drum 500 comprises a hollow shaft segment 502 that has a shaft boss 504 formed thereon for receive an outwardly protruding actuation pin 410 therein. In various circumstances, the actuation pin 410 extends through a slot 267 into a longitudinal slot 408 provided in the lock sleeve 402 to facilitate axial movement of the lock sleeve 402 when it is engaged with the articulation driver 230. A rotary torsion spring 420 is configured to engage the boss 504 on the switch drum 500 and a portion of the nozzle housing 203 as shown in FIG. 5 to apply a biasing force to the switch drum 500. The switch drum 500 can further comprise at least partially circumferential openings 506 defined therein which, referring to FIGS. 5 and 6, can be configured to receive circumferential mounts extending from the nozzle halves 202, 203 and permit relative rotation, but not translation, between the switch drum 500 and the proximal nozzle 201. The mounts also extend through openings 266 in the closure tube 260 to be seated in recesses 211 in the shaft spine 210. However, rotation of the nozzle 201 to a point where the mounts reach the end of their respective openings 506 in the switch drum 500 will result in rotation of the switch drum 500 about the shaft axis SA-SA. Rotation of the switch drum 500 will ultimately result in the rotation of the actuation pin 410 and the lock sleeve 402 between its engaged and disengaged positions. Thus, in essence, the nozzle 201 may be employed to operably engage and disengage the articulation drive system with the firing drive system in the various manners described in further detail in U.S. patent application Ser. No. 13/803,086.

The shaft assembly 200 can comprise a slip ring assembly 600 which can be configured to conduct electrical power to and/or from the end effector 300 and/or communicate signals to and/or from the end effector 300, for example. The slip ring assembly 600 can comprise a proximal connector flange 604 mounted to a chassis flange 242 extending from the chassis 240 and a distal connector flange 601 positioned within a slot defined in the nozzle halves 202, 203. The proximal connector flange 604 can comprise a first face and the distal connector flange 601 can comprise a second face which is positioned adjacent to and movable relative to the first face. The distal connector flange 601 can rotate relative to the proximal connector flange 604 about the shaft axis SA-SA. The proximal connector flange 604 can comprise a plurality of concentric, or at least substantially concentric, conductors 602 defined in the first face thereof. A connector 607 can be mounted on the proximal side of the connector flange 601 and may have a plurality of contacts, wherein each contact corresponds to and is in electrical contact with one of the conductors 602. Such an arrangement permits relative rotation between the proximal connector flange 604 and the distal connector flange 601 while maintaining electrical contact therebetween. The proximal connector flange 604 can include an electrical connector 606 which can place the conductors 602 in signal communication with a circuit board mounted to the shaft chassis 240, for example. In at least one instance, a wiring harness comprising a plurality of conductors can extend between the electrical connector 606 and the circuit board. U.S. patent application Ser. No. 13/800,067, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, is incorporated by reference in its entirety. U.S. patent application Ser. No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, is incorporated by reference in its entirety. Further details regarding slip ring assembly 600 may be found in U.S. patent application Ser. No. 13/803,086.

The shaft assembly 200 can include a proximal portion which is fixably mounted to the handle assembly 14 and a distal portion which is rotatable about a longitudinal axis. The rotatable distal shaft portion can be rotated relative to the proximal portion about the slip ring assembly 600. The distal connector flange 601 of the slip ring assembly 600 can be positioned within the rotatable distal shaft portion. Moreover, further to the above, the switch drum 500 can also be positioned within the rotatable distal shaft portion. When the rotatable distal shaft portion is rotated, the distal connector flange 601 and the switch drum 500 can be rotated synchronously with one another. In addition, the switch drum 500 can be rotated between a first position and a second position relative to the distal connector flange 601. When the switch drum 500 is in its first position, the articulation drive system may be operably disengaged from the firing drive system and, thus, the operation of the firing drive system may not articulate the end effector 300 of the shaft assembly 200. When the switch drum 500 is in its second position, the articulation drive system may be operably engaged with the firing drive system and, thus, the operation of the firing drive system may articulate the end effector 300 of the shaft assembly 200. When the switch drum 500 is moved between its first position and its second position, the switch drum 500 is moved relative to distal connector flange 601.

In various examples, the shaft assembly 200 can comprise at least one sensor configured to detect the position of the switch drum 500. The distal connector flange 601 can comprise a Hall effect sensor 605, for example, and the switch drum 500 can comprise a magnetic element, such as permanent magnet 505, for example. The Hall effect sensor 605 can be configured to detect the position of the permanent magnet 505. When the switch drum 500 is rotated between its first position and its second position, the permanent magnet 505 can move relative to the Hall effect sensor 605. In various examples, Hall effect sensor 605 can detect changes in a magnetic field created when the permanent magnet 505 is moved. The Hall effect sensor 605 can be in signal communication with a control circuit, for example. Based on the signal from the Hall effect sensor 605, a microcontroller on the control circuit can determine whether the articulation drive system is engaged with or disengaged from the firing drive system.

A surgical instrument may not be able to use a rotatable shaft assembly effectively by using general wires to communicate power and signals between a fixed shaft portion and a rotatable shaft portion of the shaft assembly because the wires may get twisted or even damaged due to the repeated rotation of the shaft assembly. One way to overcome this deficiency may be to use a ring assembly instead of wires to communicate power and signals to the rotatable shaft portion. For example, a first flange with electrodes may be attached to the fixed shaft portion and a second flange with electrodes may rotate relative to the electrodes of the first flange. A gap is necessarily formed between the first flange and the second flange to permit the rotation of the second flange relative to the first flange. In order to maintain an electrical connection during the rotation of the rotatable shaft portion, the electrodes of the first and second flanges may be exposed at an interface therebetween. The gap may permit water and/or other body fluid ingress into the area between the first and second flanges where the electrode interface resides. Accordingly, the electrode interface may become exposed to water and other body fluids during surgery. Upon touching the exposed electrodes, the water and/or body fluids may cause signal noise or even loss of power/signals.

Aspects of the present disclosure improve slip ring assemblies in surgical instruments that that are exposed to water and/or body fluids during their operation. In one arrangement, a shaft assembly may include a proximal shaft portion that can be fixably connected to a body of a surgical instrument and a distal shaft portion rotatable relative to the proximal shaft portion. The slip ring assembly may include a proximal slip ring in the proximal shaft portion and a distal slip ring in the shaft distal portion. Each of the proximal slip ring and the distal slip ring may include one or more conductors mounted on each of the proximal and distal slip rings. The conductors on the proximal and distal slip rings may be coated with a water-proof insulative layer to provide a waterproof barrier to prevent water or fluids which may be generated during surgery from reaching the conductors. A dielectric layer (e.g., high-k dielectric, such as PZT) may be located between the conductors on the proximal and distal slip rings, and the conductors of the proximal slip ring and the conductors of the distal slip ring may form capacitive channels therebetween. These capacitive channels may be used to communicate power and signals from the fixed body portion to the rotatable shaft assembly portion (e.g., an end effector) using capacitive coupling.

In this way, aspects of the present disclosure may advantageously allow the conductors to be covered with a water-proof insulative layer by forming a capacitive channel between the conductors in the distal and proximal slip rings rather than a direct connection, which may necessarily expose some portions of the electrodes to the outside. Accordingly, aspects of the present disclosure may prevent signal noise and loss of power and signals by providing an insulative barrier to prevent water or fluids from reaching the electrodes.

FIG. 10 shows a perspective partial cut-away view of a slip ring assembly 2000 according to one aspect of this disclosure and FIG. 11 shows a cross-sectional view of a portion of the slip ring assembly 2000 of FIG. 10 according to one aspect of this disclosure. The slip ring assembly 2000 may be included in a shaft assembly (e.g., shaft assembly 200). The slip ring assembly 2000 may be configured to conduct electrical power to and/or from an end effector (e.g., end effector 300) and/or communicate signals to and/or from the end effector. The slip ring assembly may include a proximal portion 2172 and a distal portion 2174. The proximal portion 2172 may be fixably connected to a body (e.g., handle assembly 14 or a chassis flange 242 of a proximal shaft portion of a shaft assembly) of a surgical instrument (e.g., surgical instrument 10). The distal portion 2174 may be fixedly connected to a distal shaft portion of a shaft assembly. The distal portion 2174 may be rotatable relative to the proximal portion 2172, for example, about a longitudinal axis. As illustrated in FIGS. 10 and 11, the slip ring assembly 2000 may include a proximal slip ring 2010 and one or more conductors 2020 mounted on the proximal slip ring 2010. The proximal slip ring 2010 and the conductors 2020 in the proximal portion 2172 may be coated with a first water-proof insulative layer 2030 to provide a waterproof barrier to prevent water or fluids which may be generated during surgery from reaching the conductors 2020. In an example aspect, the first water-proof insulative layer 2030 may cover the entire conductors 2020.

In the distal portion 2174, the slip ring assembly 2000 may also include a distal slip ring 2110 and one or more conductors 2120 mounted on the distal slip ring 2110. The distal slip ring 2110 and the conductors 2120 in the distal portion 2174 may be coated with a second water-proof insulative layer 2130 to provide a waterproof barrier to prevent water or fluids from reaching the conductors 2120. In an example aspect, the second water-proof insulative layer 2130 may cover the entire conductors 2120. In an example aspect, the first and second water-proof insulative layers 2030, 2130 may comprise an electrically insulative and water-resistant material. In an example aspect, the first and second water-proof insulative layers 2030, 2130 also may comprise a slippery material.

The proximal and distal slip rings 2010, 2110 may be positioned within a slot defined in nozzle halves (e.g., nozzle halves 202, 203). In an example aspect, the proximal and distal slip rings 2010, 2110 may be manufactured from or coated with an electrically non-conductive material. The distal slip ring 2110 may rotate relative to the proximal slip ring 2010 about the shaft axis SA-SA.

In an example aspect, a dielectric layer 2050 may be located between the first water-proof insulative layer 2030 and the second water-proof insulative layer 2130. In an example aspect, the dielectric layer 2050 may be fixably connected to the first water-proof insulative layer 2030 in the proximal portion 2172. In an example aspect, the dielectric layer 2050 may be in direct contact with the second water-proof insulative layer 2130 and the second water-proof insulative layer 2130 may comprise a slippery material such that the distal portion 2174 (e.g., the distal slip ring 2110 and the second water-proof insulative layer 2130) rotates relative to the dielectric layer 2050 smoothly with less friction with the contacted surface of the dielectric layer 2050. In another example aspect, there may be an air gap between the dielectric layer 2050 and the second water-proof insulative layer 2130.

In another example aspect, the dielectric layer 2050 may be fixably connected to the second water-proof insulative layer 2130 in the distal portion 2174. In this case, in an example aspect, the dielectric layer 2050 may be in direct contact with the first water-proof insulative layer 2030 and the first water-proof insulative layer 2030 may comprise a slippery material such that the distal portion 2174 (e.g., the distal slip ring 2110 and the dielectric layer 2050) rotates relative to the first water-proof insulative layer 2030 smoothly with less friction with the contacted surface of the first water-proof insulative layer 2030. In another example aspect, there may be an air gap between the dielectric layer 2050 and the first water-proof insulative layer 2030.

In another example aspect, the dielectric layer 2050 may be free from both of the first water-proof insulative layer 2030 and the second water-proof insulative layer 2130, for example, by being fixably connected to another component (e.g., nozzle halves 202, 203) of the surgical instrument. In this case, the dielectric layer 2050 may be in direct contact with at least one of the first water-proof insulative layer 2030 and the second water-proof insulative layer 2130, and at least one of the first water-proof insulative layer 2030 and the second water-proof insulative layer 2130 may comprise a slippery material such that the distal portion 2174 (e.g., the distal slip ring 2110 and the second water-proof insulative layer 2130) rotates relative to the dielectric layer 2050 smoothly with less friction. In another example aspect, there may be an air gap between the dielectric layer 2050 and the first water-proof insulative layer 2030 and/or between the dielectric layer 2050 and the second water-proof insulative layer 2130.

In an example aspect, the thickness 2025 of the conductors 2020 (or conductors 2120) may be in the range of about 0.001 inches to about 0.01 inches, preferably in the range of about 0.003 inches to about 0.008 inches, more preferably in the range of about 0.004 inches to about 0.006 inches. In another example aspect, the conductors 2020, 2120 may have any other suitable thickness. In an example aspect, the vertical distance 2035 between the conductors 2020 and the dielectric layer 2050 may be very small, for example, in the range of about 0.0005 inches to about 0.0015 inches, preferably in the range of about 0.0007 inches to about 0.0013 inches, more preferably in the range of about 0.0009 inches to about 0.0011 inches. In another example aspect, the conductors 2020 and the dielectric layer 2050 may have any other suitable distance. In an example aspect, a vertical distance between the conductors 2120 and the dielectric layer 2050 may be similar to the vertical distance 2035. In an example aspect, the thickness 2055 of the dielectric layer 2050 may be very thin, for example, in the range of about 0.001 inches to about 0.05 inches, preferably in the range of about 0.005 inches to about 0.03 inches, more preferably in the range of about 0.01 inches to about 0.02 inches. In another example aspect, the dielectric layer 2050 may have any other suitable thickness.

The proximal slip ring 2010 may be fixably connected to the body of the surgical instrument. For example, the proximal slip ring 2010 and the conductors 2020 of the proximal slip ring 2010 may be connected to a shaft circuit board 2070 (e.g., shaft circuit board 610) though a first electrical connector 2060 (e.g., electrical connector 606) as illustrated in FIG. 10. The circuit board 2070 may include a control circuit 2080 (e.g., a micro-chip or a microprocessor) configured to control the power and signals delivered to an end effector (e.g., end effector 300). The distal slip ring 2110 and the conductors 2120 of the distal slip ring 2110 may be connected to the end effector through a second electrical connector 2160.

The conductors 2020 of the proximal slip ring 2010 and the conductors 2120 of the distal slip ring 2110 may form capacitive channels therebetween. The control circuit 2080 may be configured to communicate the power and signals (e.g., data or any other signals) to the end effector that is electrically connected to the distal slip ring 2110 using capacitive coupling through the capacitive channels. The control circuit may use AC current to communicate power and signals to and/or from the end effector.

In an example aspect, the first and second slip rings 2010, 2110 may be in a ring shape as illustrated in FIG. 10. In another example aspect, the first and second slip rings 2010, 2110 may have any other suitable shape. In an example aspect, the conductors 2020, 2120 may comprise a metallic electrode. In another example aspect, the conductors 2020, 2120 may comprise any other electrically conductive material. In an example aspect, each of the conductors 2020 on the proximal slip ring 2010 may be matched with one of the conductors 2120 on the distal slip ring 2110 and the matched conductors may be facing each other. For example, as illustrated in FIG. 11, a conductor 2020A is matched with a conductor 2120A, and a conductor 2020B is matched with a conductor 2120B. In an example aspect, the conductors 2020, 2120 may be in a concentric circle shape, as illustrated in FIG. 10, such that the matched conductors (e.g., 2020A-2120A; 2020B-2120B) may continue to face each other while the distal portion 2174 of the slip ring assembly 2000 is rotating, maintaining the capacitive channels formed therebetween continuously. In another example aspect, the conductors 2020, 2120 may have any other suitable shape.

In an example aspect, the dielectric layer 2050 may comprise a high-k dielectric material, such as PZT (lead zirconate titanate), titanium oxide (TiO₂), tantalum oxide (Ta₂O₅), cesium oxide (CeO₂), and aluminum oxide (Al₂O₃). The materials may be used alone or in any combination thereof. As used herein, a high-k dielectric material may refer to a dielectric material having a high dielectric constant value k (e.g., greater than the k value of silicon dioxide which is around 3.9). In an example aspect, the dielectric layer 2050 may comprise a dielectric material with a very high dielectric constant (e.g., greater than about 100 to about 300), such as PZT. By using a dielectric material with a very high dielectric constant, the capacitive channels formed in the slip ring assembly 2000 may be able to have enough capacitance while keeping the thickness of the dielectric layer 2050 very thin (e.g., less than from 0.03 to 0.05 inches) without suffering from unacceptable levels of leakage current or catastrophic breakdown. In another example aspect, the dielectric layer 2050 may comprise any other suitable dielectric material (e.g., medium to low dielectric constant materials, such as silicon dioxide). In an example, the dielectric layer 2050 may be deposited on one of the slip rings above the first water-proof insulative layer 2030 or the second water-proof insulative layer 2130 (e.g., vapor deposition). In an example, the dielectric layer 2050 may be provided as a disk or wafer layer.

In an example aspect, only one of the slip rings 2010, 2110 may include a water-proof insulative layer. For example, if the distal slip ring 2110 and the conductors 2120 on the distal slip ring 2110 are coated with a water-proof insulative layer, the proximal slip ring 2010 and the conductors 2020 on the proximal slip ring 2010 may be coated with the dielectric layer 2050 (e.g., vapor deposition of a dielectric material) directly without a separate water-proof insulative layer therebetween. In this case, the dielectric layer 2050 may be water-resistant and prevent water or fluids from reaching the conductors 2020. In another example aspect, if the proximal slip ring 2010 and the conductors 2020 on the proximal slip ring 2010 are coated with a water-proof insulative layer, the distal slip ring 2110 and the conductors 2120 on the distal slip ring 2110 may be coated with the dielectric layer 2050 (e.g., vapor deposition of a dielectric material) directly without a separate water-proof insulative layer therebetween.

FIG. 12 shows a cross-sectional view of a portion of a slip ring assembly 2200 according to another aspect of this disclosure. The slip ring assembly 2200 may be included in a shaft assembly (e.g., shaft assembly 200). The slip ring assembly 2200 may have a proximal portion 2372 and a distal portion 2374. The proximal portion 2372 may be fixably connected to a body (e.g., handle assembly 14) of a surgical instrument (e.g., surgical instrument 10). The distal portion 2374 may be rotatable relative to the proximal portion 2372. As illustrated in FIG. 12, the slip ring assembly 2200 may include a proximal slip ring 2210 and one or more conductors 2220 mounted on the proximal slip ring 2210 in the proximal portion 2372. The proximal slip ring 2210 and the conductors 2220 may be coated with a first dielectric layer 2230. In an example aspect, the first dielectric layer may cover the entire conductors 2220. The first dielectric layer 2230 may provide a waterproof barrier to prevent water or fluids which may be generated during surgery from reaching the conductors 2220.

In an example aspect, the slip ring assembly 2200 also may include a distal slip ring 2310 and one or more conductors 2320 mounted on the distal slip ring 2310 in the distal portion 2374. The distal slip ring 2310 and the conductors 2320 may be coated with a second dielectric layer 2350. In an example aspect, the second dielectric layer 2350 may cover the entire conductors 2320. The second dielectric layer 2350 may provide a waterproof barrier to prevent water or fluids which may be generated during surgery from reaching the conductors 2320. The conductors 2220, 2320 may form capacitive channels therebetween.

In an example aspect, the first and second dielectric layers 2230, 2350 may comprise a high-k dielectric material, such as PZT (lead zirconate titanate), titanium oxide (TiO₂), tantalum oxide (Ta₂O₅), cesium oxide (CeO₂), aluminum oxide (Al₂O₃), or an epoxy material with a high k value (e.g., having a dielectric constant higher than 3.9). The materials may be used alone or in any combination thereof. In an example aspect, at least one of the first and second dielectric layers 2230, 2350 may comprise a dielectric material with a very high dielectric constant (e.g., greater than about 100 to about 300), such as PZT. In another example aspect, the first and second dielectric layers 2230, 2350 may comprise any other suitable dielectric material (e.g., medium to low dielectric constant materials, such as silicon dioxide).

In an example aspect, the first dielectric layer 2230 may comprise a dielectric material different from the second dielectric layer 2350. For example, the first dielectric layer 2230 may comprise an epoxy material while the second dielectric layer 2350 comprises titanium oxide or PZT (e.g., vapor deposited dielectric layer). In another example aspect, the first dielectric layer 2230 may comprise a dielectric material that is the same as the second dielectric layer 2350.

In an example aspect, the slip ring assembly 2200 may include a third dielectric layer 2250 fixably attached on the first dielectric layer 2230. For example, a dielectric disc/wafer may be glued to the first dielectric layer 2230 or a dielectric layer is vapor deposited on the first dielectric layer 2230. In this case, in an example, there may be an air gap 2360 between the second dielectric layer 2350 and the third dielectric layer 2250 to facilitate a smooth rotation of the distal portion 2374 relative to the third dielectric layer 2250. In another example aspect, there may be no air gap between the second dielectric layer 2350 and the third dielectric layer 2250, and a slippery insulative layer may be coated either on the second dielectric layer 2350 or on the third dielectric layer 2250.

In another example aspect, the third dielectric layer 2250 may be fixably attached on the second dielectric layer 2350. In this case, in an example, there may be an air gap between the first dielectric layer 2230 and the third dielectric layer 2250 to facilitate a smooth rotation of the distal portion 2374, including the third dielectric layer 2250, relative to the first dielectric layer 2230. In another example aspect, there may be no air gap between the first dielectric layer 2230 and the third dielectric layer 2250, and a slippery insulative layer may be coated either on the first dielectric layer 2230 or on the third dielectric layer 2250.

In another example aspect, the third dielectric layer 2250 may be free from both of the first dielectric layer 2230 and the second dielectric layer 2350, for example, by being fixably connected to another component (e.g., nozzle halves 202, 203) of the surgical instrument. In this case, in an example, there may be an air gap between the third dielectric layer 2250 and at least one of the first and second dielectric layers 2230, 2350. In another example aspect, there may be no air gap, but instead there may be a slippery insulative layer between the third dielectric layer 2250 and at least one of the first and second dielectric layers 2230, 2350.

In an example aspect, the third dielectric layer 2250 may comprise a high-k dielectric material, such as PZT (lead zirconate titanate), titanium oxide (TiO₂), tantalum oxide (Ta₂O₅), cesium oxide (CeO₂), aluminum oxide (Al₂O₃) or an epoxy material with a high k value (e.g., having a dielectric constant higher than 3.9). The materials may be used alone or in any combination thereof. In an example aspect, the third dielectric layer 2250 may comprise a dielectric material with a very high dielectric constant (e.g., greater than about 100 to about 300), such as PZT. In another example aspect, the third dielectric layer 2250 may comprise any other suitable dielectric material (e.g., medium to low dielectric constant materials, such as silicon dioxide).

In an example aspect, the dielectric constant of the second dielectric layer 2350 and/or the third dielectric layer 2250 may be greater than the dielectric constant of the first dielectric layer 2230. In another example aspect, the dielectric constant of the first dielectric layer 2230 may be greater than the dielectric constant of the second dielectric layer 2350 and/or the third dielectric layer 2250. In an example aspect, the third dielectric layer 2250 may comprise a dielectric material different from the second dielectric layer 2350. In another example aspect, the third dielectric layer 2250 may comprise a dielectric material that is the same as the second dielectric layer 2350.

In an example aspect, the thickness 2225 of the conductors 2220 and/or the thickness 2325 of the conductors 2320 may be in the range of about 0.001 inches to about 0.01 inches, preferably in the range of about 0.003 inches to about 0.008 inches, more preferably in the range of about 0.004 inches to about 0.006 inches. In another example aspect, the conductors 2220, 2320 may have any other suitable thickness. In an example aspect, the thickness 2355 of the second dielectric layer 2350 may be in the range of about 0.001 inches to about 0.01 inches, preferably in the range of about 0.002 inches to about 0.005 inches, more preferably in the range of about 0.003 inches to about 0.004 inches. In another example aspect, the second dielectric layer 2350 may have any other suitable thickness. In an example aspect, the air gap 2260 between the third dielectric layer 2250 and the second dielectric layer 2350 (or any other air gap discussed herein) may be very thin, for example, less than 0.01 inches, preferably less than 0.005 inches, more preferably less than 0.001 inches. In another example aspect, the air gap 2260 may have any other suitable distance.

In an example aspect, the vertical distance 2235 between the conductors 2220 and the third dielectric layer 2250 may be very small, for example, in the range of about 0.0005 inches to about 0.0015 inches, preferably in the range of about 0.0007 inches to about 0.0013 inches, more preferably in the range of about 0.0009 inches to about 0.0011 inches. In another example aspect, the conductors 2220 and the third dielectric layer 2250 may have any other suitable distance. In an example aspect, the thickness 2255 of the third dielectric layer 2250 may be very thin, for example, in the range of about 0.001 inches to about 0.01 inches, preferably in the range of about 0.002 inches to about 0.007 inches, more preferably in the range of about 0.003 inches to about 0.005 inches. In another example aspect, the third dielectric layer 2250 may have any other suitable thickness.

Remaining features and characteristics of the slip ring assembly 2200 illustrated and described with respect to FIG. 12 in which the conductors 2220, 2320 are mounted on the slip rings 2210, 2310 can otherwise be similar or the same as those described with the embodiments depicted in FIGS. 10-11, including but not limited to components, arrangements, and shapes of any of the slip rings 2210, 2310 or the conductors 2220, 2320, as well as the possible presence of electrical connectors 2060, 2160, shaft circuit board 2070, control circuit 2080 as described and illustrated herein.

FIG. 13 shows a block diagram of the circuit of a surgical instrument, illustrating interfaces between a control circuit 2410 (e.g., control circuit 2080), a power source 2420 (e.g., power source 90), a slip ring assembly 2450 (e.g., slip ring assemblies 2000, 2200), and an end effector 2430 (e.g., end effector 300) according to one aspect of this disclosure. As illustrated in FIG. 13, the slip ring assembly 2450 may include one or more capacitive channels 2440A-C formed by conductors on the proximal and distal slip rings. The control circuit 2410 may be configured to communicate power and signals to the end effector 2430 using capacitive coupling through the capacitive channels 2440A-C.

In an example aspect, each capacitive channel 2440A-C may receive/transmit different types of signals/power. For example, the control circuit 2410 may use a first capacitive channel 2440A for a first signal or data, a second capacitive channel 2440B for a second signal or data, and a third capacitive channel 2440C for power. In another example embodiment, the control circuit 2410 may receive/transmit different types of signals/power using the same capacitive channel. For example, the first capacitive channel 2440A may be used to receive/transmit both the power and signals.

The foregoing description has set forth aspects of devices and/or processes via the use of block diagrams, flowcharts, and/or examples, which may contain one or more functions and/or operation. Each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In one aspect, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), Programmable Logic Devices (PLDs), circuits, registers and/or software components, e.g., programs, subroutines, logic and/or combinations of hardware and software components, logic gates, or other integrated formats. Some aspects disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure.

The mechanisms of the disclosed subject matter are capable of being distributed as a program product in a variety of forms, and that an illustrative aspect of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include the following: a recordable type medium such as a floppy disk, a hard disk drive, a Compact Disc (CD), a Digital Video Disk (DVD), a digital tape, a computer memory, etc.; and a transmission type medium such as a digital and/or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link (e.g., transmitter, receiver, transmission logic, reception logic, etc.).

The foregoing description of these aspects has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the precise form disclosed. Modifications or variations are possible in light of the above teachings. These aspects were chosen and described in order to illustrate principles and practical application to thereby enable one of ordinary skill in the art to utilize the aspects and with modifications as are suited to the particular use contemplated. It is intended that the claims submitted herewith define the overall scope.

Various aspects of the subject matter described herein are set out in the following examples:

EXAMPLE 1

A surgical shaft assembly comprising a slip ring assembly. The slip ring assembly comprises a first connector, a first conductor mounted on the first connector, and a first water-proof insulative layer on the first conductor. The slip ring assembly further comprises a second connector rotatable relative to the first connector, a second conductor mounted on the second connector, and a second water-proof insulative layer on the second conductor. The slip ring assembly further comprises a dielectric layer located between the first water-proof insulative layer and the second water-proof insulative layer, wherein the first conductor and the second conductor are configured to form a capacitive channel therebetween.

EXAMPLE 2

The surgical shaft assembly of Example 1, wherein at least one of the first connector and the second connector comprises a slip ring.

EXAMPLE 3

The surgical shaft assembly of one or more of Example 1 through Example 2, wherein the dielectric layer is fixably connected to the first water-proof insulative layer.

EXAMPLE 4

The surgical shaft assembly of one or more of Example 1 through Example 3, wherein the dielectric layer comprises a PZT.

EXAMPLE 5

The surgical shaft assembly of one or more of Example 1 through Example 4, wherein at least one of the first water-proof insulative layer and the second water-proof insulative layer comprises a slippery material.

EXAMPLE 6

The surgical shaft assembly of one or more of Example 1 through Example 5, further comprising a control circuit electrically connected to the first conductor.

EXAMPLE 7

The surgical shaft assembly of Example 6, further comprising an end effector electrically connected to the second conductor, wherein the control circuit is configured to communicate power and signals to the end effector through the capacitive channel.

EXAMPLE 8

A slip ring assembly for use with a surgical shaft assembly. The slip ring assembly comprises a first connector, a first conductor mounted on the first connector, and a first dielectric layer on the first conductor. The slip ring assembly further comprises a second connector rotatable relative to the first connector, a second conductor mounted on the second connector, and a second dielectric layer on the second conductor, wherein the first conductor and the second conductor are configured to form a capacitive channel therebetween.

EXAMPLE 9

The slip ring assembly of Example 8, further comprising a third dielectric layer on the first dielectric layer.

EXAMPLE 10

The slip ring assembly of Example 9, wherein the second dielectric layer and the third dielectric layer are spaced apart such that a gap is formed therebetween.

EXAMPLE 11

The slip ring assembly of one or more of Example 8 through Example 10, wherein the second dielectric layer comprises a vapor-deposited PZT.

EXAMPLE 12

The slip ring assembly of one or more of Example 8 through Example 11, wherein the first dielectric layer comprises an epoxy material.

EXAMPLE 13

The slip ring assembly of one or more of Example 9 through Example 12, wherein the third dielectric layer comprises a PZT wafer.

EXAMPLE 14

The slip ring assembly of one or more of Example 8 through Example 13, further comprising a control circuit electrically connected to the first conductor.

EXAMPLE 15

A surgical shaft assembly, comprising a first shaft portion and a second shaft portion rotatable relative to the first shaft portion. The first shaft portion comprises a first slip ring, a first plurality of conductors mounted on the first slip ring, and a first water-proof insulative layer on the first slip ring. The second shaft portion comprises a slip ring, a second plurality of conductors mounted on the second slip ring, a second water-proof insulative layer on the second slip ring, and a dielectric layer located between the first water-proof insulative layer and the second water-proof insulative layer, wherein the first plurality of conductors and the second plurality of conductors are configured to form a plurality of capacitive channels therebetween.

EXAMPLE 16

The surgical shaft assembly of Example 15, further comprising a control circuit electrically connected to the first plurality of conductors.

EXAMPLE 17

The surgical shaft assembly of Example 16, further comprising an end effector that is electrically connected to the second plurality of conductors, wherein control circuit is configured to communicate power and signals to the end effector through the plurality of capacitive channels.

EXAMPLE 18

The surgical shaft assembly of one or more of Example 15 through Example 17, wherein the dielectric layer is fixably connected to the first water-proof insulative layer.

EXAMPLE 19

The surgical shaft assembly of one or more of Example 15 through Example 18, wherein the dielectric layer comprises a PZT.

EXAMPLE 20

The surgical shaft assembly of one or more of Example 15 through Example 19, wherein at least one of the first water-proof insulative layer and the second water-proof insulative layer comprises a slippery material.

EXAMPLE 21

A surgical instrument, comprises a surgical end effector, a control circuit, and a connector assembly. The connector assembly comprises a first connector comprising a first conductor electrically coupled to the surgical end effector and a second connector comprising a second conductor spaced apart from the first conductor, wherein the second conductor is electrically coupled to the control circuit, wherein the first connector is rotatable relative to the second connector, wherein the first conductor is capacitively coupled to the second conductor defining a capacitive channel therebetween for transmitting an electrical signal between the surgical end effector and the control circuit.

EXAMPLE 22

A surgical instrument, comprises a surgical end effector, a control circuit, and a connector assembly. The connector assembly comprises a first connector comprising a first conductor electrically coupled to the surgical end effector, and a second connector comprising a second conductor spaced apart from the first conductor, wherein the second conductor is electrically coupled to the energy source, wherein the first connector is rotatable relative to the second connector, wherein the first conductor is capacitively coupled to the second conductor defining a capacitive channel therebetween for transmitting energy from the energy source to the surgical end effector. 

What is claimed is:
 1. A surgical shaft assembly comprising a slip ring assembly, the slip ring assembly comprising: a first connector; a first conductor mounted on the first connector; a first water-proof insulative layer on the first conductor; a second connector rotatable relative to the first connector; a second conductor mounted on the second connector; a second water-proof insulative layer on the second conductor; a dielectric layer located between the first water-proof insulative layer and the second water-proof insulative layer; and wherein the first conductor and the second conductor are configured to form a capacitive channel therebetween.
 2. The surgical shaft assembly of claim 1, wherein at least one of the first connector and the second connector comprises a slip ring.
 3. The surgical shaft assembly of claim 1, wherein the dielectric layer is fixably connected to the first water-proof insulative layer.
 4. The surgical shaft assembly of claim 1, wherein the dielectric layer comprises a PZT.
 5. The surgical shaft assembly of claim 1, wherein at least one of the first water-proof insulative layer and the second water-proof insulative layer comprises a slippery material.
 6. The surgical shaft assembly of claim 1, further comprising a control circuit electrically connected to the first conductor.
 7. The surgical shaft assembly of claim 6, further comprising an end effector electrically connected to the second conductor, wherein the control circuit is configured to communicate power and signals to the end effector through the capacitive channel.
 8. A slip ring assembly for use with a surgical shaft assembly, the slip ring assembly comprising: a first connector; a first conductor mounted on the first connector; a first dielectric layer on the first conductor; a second connector rotatable relative to the first connector; a second conductor mounted on the second connector; a second dielectric layer on the second conductor; and wherein the first conductor and the second conductor are configured to form a capacitive channel therebetween.
 9. The slip ring assembly of claim 8, further comprising a third dielectric layer on the first dielectric layer.
 10. The slip ring assembly of claim 9, wherein the second dielectric layer and the third dielectric layer are spaced apart such that a gap is formed therebetween.
 11. The slip ring assembly of claim 10, wherein the second dielectric layer comprises a vapor-deposited PZT.
 12. The slip ring assembly of claim 11, wherein the first dielectric layer comprises an epoxy material.
 13. The slip ring assembly of claim 12, wherein the third dielectric layer comprises a PZT wafer.
 14. The slip ring assembly of claim 8, further comprising a control circuit electrically connected to the first conductor.
 15. A surgical shaft assembly, comprising: a first shaft portion, comprising: a first slip ring; a first plurality of conductors mounted on the first slip ring; and a first water-proof insulative layer on the first slip ring; a second shaft portion rotatable relative to the first shaft portion, wherein the second shaft portion comprises: a second slip ring; a second plurality of conductors mounted on the second slip ring; a second water-proof insulative layer on the second slip ring; and a dielectric layer located between the first water-proof insulative layer and the second water-proof insulative layer; and wherein the first plurality of conductors and the second plurality of conductors are configured to form a plurality of capacitive channels therebetween.
 16. The surgical shaft assembly of claim 15, further comprising a control circuit electrically connected to the first plurality of conductors.
 17. The surgical shaft assembly of claim 16, further comprising an end effector that is electrically connected to the second plurality of conductors, wherein the control circuit is configured to communicate power and signals to the end effector through the plurality of capacitive channels.
 18. The surgical shaft assembly of claim 15, wherein the dielectric layer is fixably connected to the first water-proof insulative layer.
 19. The surgical shaft assembly of claim 15, wherein the dielectric layer comprises a PZT.
 20. The surgical shaft assembly of claim 15, wherein at least one of the first water-proof insulative layer and the second water-proof insulative layer comprises a slippery material.
 21. A surgical instrument, comprising: a surgical end effector; a control circuit; and a connector assembly, comprising: a first connector comprising a first conductor electrically coupled to the surgical end effector; and a second connector comprising a second conductor spaced apart from the first conductor, wherein the second conductor is electrically coupled to the control circuit, wherein the first connector is rotatable relative to the second connector, wherein the first conductor is capacitively coupled to the second conductor defining a capacitive channel therebetween for transmitting an electrical signal between the surgical end effector and the control circuit.
 22. A surgical instrument, comprising: a surgical end effector; an energy source; and a connector assembly, comprising: a first connector comprising a first conductor electrically coupled to the surgical end effector; and a second connector comprising a second conductor spaced apart from the first conductor, wherein the second conductor is electrically coupled to the energy source, wherein the first connector is rotatable relative to the second connector, wherein the first conductor is capacitively coupled to the second conductor defining a capacitive channel therebetween for transmitting energy from the energy source to the surgical end effector. 